import java.util.ArrayList;
import java.util.Vector;

public class Main15 {
    public static void main(String[] args) {
        Object testObject = new ArrayList();
        displayObjectClass(testObject);
    }
    public static void displayObjectClass(Object o) {
        if(o instanceof Vector){
            System.out.println("对象是 java.util.Vector 类的实例");
        }else if(o instanceof ArrayList){
            System.out.println("对象是 java.util.ArrayList 类的实例");
        }else {
            System.out.println("对象是 " + o.getClass() + " 类的实例");
        }
    }
}